Membrane aid for hearing



March 13, 1956 ANNAs 2,738,025

MEMBRANE AID FOR HEARING Filed Dec. 51, 1952 INVENTOR. PAUL J. ANNAS BY W k W ATTO RNEYS United States Patent O MEMBRANE AH) FOR HEARING Paul J. Annas, Cleveland, Ohio Application December 31, 1952, Serial No. 328,963

9 Claims. (Cl. 181-23) The present invention relates to a hearing aid and more particularly to a membrane formation adapted to be inserted in the human ear.

Many persons suffer from complete or partial deafness in one or both ears resulting from perforations in the ear drum or from the absence of the ear drum entirely. Such conditions are brought about by various causes, such as illness or accident, but irrespective of the cause, an impairment of hearing ability results.

My invention was developed to overcome this impairment, when such impairment results solely from perforations in the ear drum or from the absence of the ear drum. My invention is not applicable to alleviate deafness where such deafness results from injury to the auditory nerves, disease formation in the auditory canal or allied causes.

It is the primary object of my invention to provide a hearing aid which requires no electrical energization to effect amplification of sound to the auditory nerve.

Another object of my invention is to provide ahearing aid in the form of a membrane which serves as an eardrum.

A further object of my invention is to provide a membranous hearing aid of the character described which is concealed from view when in use by the wearer.

Still another object of my invention is to provide an extremely thin, flexible material for the membranous hearing aid, which is light in Weight and inexpensive to produce.

Other objects and advantages of the invention will be apparent during the course of the following description.

Fig. 1 is a side elevation of a membranous hearing aid embodying the features of my invention.

Fig. 2 is a view similar to Fig. 1, showing a modified form of my invention.

Fig. 3 is a longitudinal cross-section taken on line 3-3 of Fig. 1.

Fig. 4 is illustrative of a step in my method of forming the membrane film.

Fig. 5 is a fragmentary view showing the manner in which the film forms.

Fig. 6 is a View showing another step in the formation of the hearing aid shown in Fig. 1.

Referring more particularly to the drawings, I have shown in Fig. l, on an enlarged scale, a membranous cone or hearing aid 10 embodying the features of my invention. As indicated, the hearing aid is substantially of hollow conical form, having an open end 11, tapered sides or walls 12 and a blunt end or nose 13, which does not fol-- low the curvature of the wall 12, but, instead, is flat or plane.

As best seen in Fig. 3, the wall 12 is of a uniform thickness which is on the order of two thousandths to five thousandths of an inch. The wall 12 converges from the opening 11 toward the end 13, so as to direct or funnel sound vibrations toward the nose 13.

The length or height of the cone 10 may vary some- 2,738,025 Patented Mar. 13, 1956 what, but is nominally under one-half inch and may be as small as one-quarter inch.

In utilizing the hearing aid, it is inserted into the channel of the outer ear of the wearer, with the open end 11 facing exteriorly. The nose 13 of the formed membrane 10 is located and positioned in the channel so as to substantially coincide with the normal location of the ear drum.

It will be understood that the end 13 may substantially seal the opening between the outer ear and the middle ear which results from the absence of the ear drum, and thus be in proximity to or contact with the bones of the middle ear. In' those instances where the eardrum has only a large perforation, the end 13 of the cone will be placed in sealing engagement with the opening in the eardrum itself.

As shown in Fig. 2, the hearing aid may be formed or molded to particularly conform to peculiarities of the outer ear channel. The cone 10', which is shown in Fig. 2, shows the appearance of a cone which is formed to a particular configuration.

It is of paramount importance that the material, out of which the cone 10 is formed, have the particular characteristics necessary for utilization as a hearing aid. I have found that the following properties are necessary in the material, in order that it may be successfully used for its intended purpose.

(a) It must be capable of being formed in extremely thin sections.

(b) It must be sensitive to sound vibrations.

(c) It must be capable of being molded to a conelike form.

(d) It must be free from brittleness.

(2) It must be resistant to moisture and conditions of mild acidity.

(f) It must have a relatively smooth surface, so as not to cause irritations to the ear passage.

(g) It must have a degree of firmness or rigidity surlicient to retain its form or shape.

(It) It must be light in weight.

In addition to the foregoing, it is also desirable that the material have an antiseptic quality and that it be lubricant-bearing, i. e., have an oily surface.

In order to obtain the above-enumerated properties, I utilize a lacquer-like film developed by accelerated evaporation of a film forming material in the liquid phase.

The liquid is compounded by intimately mixing the following ingredients in the indicated proportions, which are approximate:

1 part filrn forming solution 1-2 parts thinner 1 part petroleum jelly (petrolatum) 6-12 parts oil To the foregoing, it is desirable to add a small amount of a pharmaceutical antiseptic or germicidal agent such as sulfathiazole which may comprise about 1% or less of the mixture.

The plastic film-forming solution may conform generally to that of commercial lacquer, consisting nominally of:

15% nitro-cellulose 5% plasticizers 5% resins 50% solvent 25% diluent or thinner the particular constituents being well known in the art.

The additional thinner, such as naphtha or benzol, is added to further reduce the viscosity of the nitro-cellulose solution.

afisspss The oil and the petroleum jelly give the composition the necessary pliability and lubricating qualities, as well as contributing to the ability of the resultant film to transmit sound vibrations. I have found that a low-melting I vegetable oil, such .as olive oil or casltonoil, is particularly well suited for the purposes of my invention. The use of the 'petrolatum is desirable, but. not -mandatory.

The mixture of the foregoing ingredients is van oily liquid at room temperature. The;germicidal agent may be added if desired. In Figs. 4 and 5, I haveillustrated a step in the formation of the resultant film 14. In order to obtain a film of extreme thinness, I deposit :the compounded liquid L .on the surface of a water bath W, which has .a temperature froml-l60 F. The-water maybe contained in .any suitablereceptacle or vessel V.

Thefilmrforming liquid L'is deposited upon the surface of the heated 'water W by any suitable means. In Fig. 4, I have shown a dropper D which is conveniently used when only a small quantity, say, about two squareinches, of film isto be produced.

The liquid L is deposited rapidly and -.in a sutficient volume to give the desired thickness. If the surface of the water is very thinly covered by the volume of liquid L, a film of minimum thickness is obtained. This would be on the order of 001-002 inch. If aslightly larger volume of liquidL is used, the thicknessof the-resultant film is increased. As previously -indicated, l have found that a film having a thickness of 002-.005 inch is ,desirable, and, therefore, I depositzenough liquid ,1. to just cover the surface of the water.

.Theentire volume of liquid L must be depositedrapidly so as to prevent stratification of the resultant film.

After deposition, the heat of .the water causes accelerated evaporation of the volatile constituents of the liquid L and within a very short time, a pliable plastic film is formed on the surface of the water.

-It will be understood that theliquid L is not miscible with the water and has a lower specific gravitythanthe water, therefore, the liquid will form a surface layer .on the water, as shown in Fig. 5.

The film 14may be lifted from the water W and it is desirable that it be formed while it is still warm and in a very pliable condition.

In Fig. 6, I have shown a conicalformior .mold 15 which may be utilized to form the cone 10. The still pliable film 14 may be placed over the block 15 and manually caused to conformto the conical shape, as indicated in broken lines in Fig. 6.

After the film 14 has cooled, it .is removed from the mold 15 and is ready to be'inserted in the outer ear passage of the wearer.

The film is still pliable enough, even after it has cooled or set, so that it can adapt itself to .theeonfigurations of the ear channel. The cone'10 has asmooth,soily surface which does not irritate the ear channel and is resistant to deterioration from the effects of water or mildly acid conditions.

The film, of which'the cone is formed, appears to form a matrix for minute liquid inclusions :of the oily constituents of the liquid L, and apparentlythas tiny globules of the vegetable oil entrapped therein. This liquid phase of the film is believed to be of considerable importance in imparting those improved sound transmission characteristics to the film which make it especially suitable for use as a membranous hearing aid in the form of a substitute or auxiliary eardrum.

It is to be understood that the form of my invention, herewith shown and described, is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts-may be resorted to, without departing from the spirit of my invention, or the scope of the subjoined claims.

This application is a continuationin part of my copending application Serial No. 160,564 filed May 6, 1950, now Patent No. 2,633,927, issued April 7, -3.

Having thus described my invention, 1 claim:

1. A membranous artificial ear drum element consisting of a plastic film formed to conform to the configuration of the channel of the human outerear, said element being substantially conical in form and having an open end and a closed end, and said film containing liquid phase inclusions.

2. A membranous artificial ear drum element consisting of a matrix of plastic film and inclusions of a lowmelting vegetable .oil.

3. A membranous artificial ear drum element as defined in claim 2 in whichsaid plastic film has a thickness of less than .005 inch.

4. A membranous artificial ear drum element as defined in claim 2 in which saidplastic film has a thickness of .002-005 inch.

5. A membranous artificial ear drum element as definedin claim 2in which said plastic film has a thickness of less than .005 inch and is formed into a hollow substantially conical form.

6. A membranous artificialeardrum element consisting of .a hollow substantially cone-shaped formed plastic film containing a liquid phase of a low melting vegetable oil.

7. A membranous artificial ear drum element consisting of a hollow substantially cone-shaped formed plastic film having a thickness ofless than .005 inch and containing inclusions of a liquid phaseof a low melting oil.

8. A membranous artificial ear drum element consisting I of aplastic nitro-cellulose film having a thickness .of less than .005 inch andcontaining inclusions of a liquid phase of a low melting oil.

9. A membranous artificial ear drumelement. as defined in-claim 8, in which said oil is ,olive oil.

References Cited in the file of this patent UNITED STATES PATENTS Cam: a 

1. A MEMBRANOUS ARTIFICIAL EAR DRUM ELEMENT CONSISTING OF A PLASTIC FILM FORMED TO CONFORM TO THE CONFIGURATION OF THE CHANNEL OF THE HUMAN OUTER EAR, SAID ELEMENT BEING SUBSTANTIALLY CONICAL IN FROM AND HAVING AN OPEN END AND A CLOSED END, AND SAID FILM CONTAINING LIQUID PHASE INCLUSIONS.
 8. A MEMBRANOUS ARTIFICIAL EAR DRUM ELEMENT CONSISTING OF A PLASTIC INTRO-CELLULOSE FILM HAVING A THICKNESS OF LESS THAN .005 INCH AND CONTAINING INCLUSIONS OF A LIQUID PHASE OF A LOW MELTING OIL. 